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Blake W. Sauey

Publications and source records attributed to Blake W. Sauey.

7 recordsLinked to original sources

A novel tool to selectively deliver a control agent to filter-feeding silver and bighead carp

Invasive carp pose substantial economic and ecological damage when populations are widespread in freshwater systems within the United States. Resource managers in the United States have few chemical control tools to selectively remove nuisance fish. This study examined whether Antimycin–A (antimycin) wax encapsulated microparticles could cause selective lethality in invasive carps. The antimycin microparticles were selective toward bighead carp ( Hypophthalmichthys nobilis ) and silver carp ( Hypophthalmichthys molitrix ) across multiple experimental scales. Microparticles applied in experimental pond studies caused approximately 50 percent lethality in invasive carp. Effluent pond studies performed at Rathbun Fish Hatchery (Moravia, Iowa) caused silver carp lethality at a lower rate than previous pond or laboratory studies (approximately 1 percent); however, minimal effects on other fish species were observed. The antimycin microparticle formulation shows the ability to cause lethality in filter-feeding invasive carp relative to other fish species and demonstrated the plausibility for delivering a typically nonselective toxicant in a selective manner to specific species based on their physiological feeding traits.

Open-File Report

Toxicity of a management bait for grass carp (Ctenopharyngodon idella) incorporated with Antimycin A

No current technology can specifically target grass carp ( Ctenopharyngodon idella ) for control within aquatic ecosystems. Rotenone and Carbon Dioxide-Carp are currently the only available registered pesticides for grass carp; they are nonselective and typically applied throughout the water, equally exposing target and native species. A more selective control tool or pesticide application could be used by resource managers to support mitigation efforts. Development of delivery systems that exploit carp feeding strategies could increase selectivity of pesticides and minimize effects on native fishes. A pesticide with selective delivery could be less labor intensive and used within an integrative pest management strategy. The present study examined Antimycin A toxicity in juvenile and sub-adult grass carp and rainbow trout ( Oncorhynchus mykiss ) across two routes of exposure. Water-based toxicity studies were used to calculate the concentration to cause lethality in 50% of treated fish (LC 50 ) at 24-h, while oral gavage toxicity studies were used to calculate the dose to cause lethality in 50% of treated grass carp and rainbow trout (LD 50 ) 24- to 96-h. Although rainbow trout were more sensitive than grass carp to Antimycin A through water-based exposure, oral toxicity was similar between species, even with inherent gastrointestinal morphological differences. Successful delivery of a lethal dose of Antimycin A to grass carp was achieved through an oral route of exposure using the rapeseed bait and shows promise for registration as a control tool and eventual use in pest management plans. Although a lethal dose of Antimycin A could be incorporated into a single bait pellet, more bait was required to achieve desired mortality when fed to fish under laboratory conditions.

Ecotoxicology

Tests in a semi-natural environment suggest that bait and switch strategy could be used to control invasive Common Carp

Common Carp ( Cyprinus carpio Linnaeus, 1758), is a highly invasive species that has had profound effects on biodiversity and ecosystem services. Many Carp management methods have been applied including physical removal, pesticide treatments of whole lakes, and water drawdowns. Herein, we tested key elements of a potential “bait and switch” approach in which corn could be used to induce feeding aggregations of Carp and then switched for corn pellets with a pesticide Antimycin-A (ANT-A) to selectively target the Carp. First, laboratory experiments were used to determine if addition of lethal concentrations of ANT-A to corn pellets deterred Carp from eating corn-based food pellets. Second, a pond experiment tested if a corn-based bait containing ANT-A functioned as a species-specific Carp management tool in a semi-natural environment with three common native fishes: White Sucker ( Catostomus commersonii Lacepède, 1803), Yellow Perch ( Perca flavescens Mitchill, 1814), and Bluegill ( Lepomis macrochirus Rafinesque, 1819). The use of baited sites by Carp and native species was monitored using passive integrated transponder (PIT) tags. Mortality of each species and presence of corn in their digestive tracts was also monitored. Our laboratory experiment showed that presence of ANT-A did not deter Carp from consuming the pellets. The pond experiment showed that only Carp perished in significant numbers once toxic bait was applied. Further, only Carp increased their use of baited sites once baiting began, and only Carp had corn in their digestive tracts. Overall, our results indicate that corn might function as a species-specific Carp attractant in systems of North American Midwest and that corn-based bait can be used to effectively conceal a lethal dose of ANT-A. Further research is necessary to refine this potential management tool, specifically investigating the behavioral and social dynamics of Carp aggregating at sites baited with corn to enhance the temporal and spatial specificity of pesticide application.z

Management of Biological Invasions

Profiles of digestive enzymes of two competing planktivores, silver carp and gizzard shad, differ

Typically, studies in digestive physiology in fish focus on a few enzymes and provide insight into the specific processes of the enzyme in a targeted species. Comparative studies assessing a wide number of digestive enzymes on fishes that compete for food resources are lacking, especially in the context of an introduced species. It is generally thought that the invasive silver carp (SVC; Hypophthalmichthys molitrix ) directly compete for food resources with the native gizzard shad (GZS; Dorosoma cepedianum ) in waters where they coexist. We compared 19 digestive enzymes between SVC and GZS throughout a year and in two rivers in the Midwestern United States: Illinois River and Wabash River. All digestive enzymes analyzed were detected in both SVC and GZS in both rivers. However, the profiles of the digestive enzymes varied by species. Alkaline phosphatase, valine arylamidase, acid phosphatase, naphthol-AS-BI-phosphohydrolase and N-acetyl-β-glucosaminidase were all much higher in SVC than in GZS. Differences between digestive enzyme profiles were also observed between rivers and months. This study demonstrates the utility of using an ecological approach to compare physiological features in fishes.

Ichthyological Research

Assessing the efficacy of corn-based bait containing antimycin-a to control common carp populations using laboratory and pond experiments

Strategic use of oral toxicants could allow for practical and sustainable control schemes for the invasive common carp ( Cyprinus carpio, or ‘carp’) if a toxicant selectively targeted carp and not native species. In this study, we incorporated antimycin-a (ANT-A), a known fish toxicant, into a corn-based bait and conducted a series of experiments to determine its toxicity, leaching rate, and species-specificity. Our results showed that ANT-A was lethal to carp at doses ≥ 4 mg/kg and that the amount of ANT-A that leached out of the bait in 72 h was not lethal to carp or bluegill ( Lepomis macrochirus ). Species-specificity trials were conducted in 227 L tanks, in which carp were stocked with three native species representing families that occur sympatrically with carp in our study region: the fathead minnow ( Pimephales promelas ), yellow perch ( Perca flavescens ) and bluegill. These trials showed high mortality of carp (46%) and fathead minnows (76%) but no significant mortality of perch or bluegill. Finally, a pond study, which used the same species composition except for fathead minnows, resulted in 37% morality among adult carp and no mortality among perch or bluegill. Our results suggest that corn-based bait that contains ANT-A could be used to selectively control carp in ecosystems dominated by percids or centrarchids, such as lakes across the Great Plains ecoregion of North America, where carp are especially problematic.

Biological Invasions

Digestive physiology comparisons of aquatic invertebrates in the Upper Mississippi River Basin

Limited information is available on the composition of digestive enzymes present in unionid mussels and the zebra mussel, Dreissena polymorpha . Available information is nearly exclusive to species used for culture purposes. A commercially available enzyme assay kit was used to examine the effect of habitat within an ecosystem, season, and species on the activities of several digestive enzymes. We used Amblema plicata to represent native unionids, D. polymorpha , and also Hydropsyche orris as an outgroup to compare differences between mussels and other macroinvertebrates. The data indicated that neither location nor time affect the activities of the digestive enzymes tested; species was the only factor to affect the activity. Differences were found mostly between four enzymes: naphthol-AS-BI-phosphohydrolase, acid phosphatase, alkaline phosphatase, and β-galactosidase.

Upper Mississippi River Basin

Preliminary characterization of digestive enzymes in freshwater mussels

Resource managers lack an effective chemical tool to control the invasive zebra mussel Dreissena polymorpha . Zebra mussels clog water intakes for hydroelectric companies, harm unionid mussel species, and are believed to be a reservoir of avian botulism. Little is known about the digestive physiology of zebra mussels and unionid mussels. The enzymatic profile of the digestive glands of zebra mussels and native threeridge ( Amblema plicata ) and plain pocketbook mussels ( Lampsilis cardium ) are characterized using a commercial enzyme kit, api ZYM, and validated the kit with reagent-grade enzymes. A linear correlation was shown for only one of nineteen enzymes, tested between the api ZYM kit and a specific enzyme kit. Thus, the api ZYM kit should only be used to make general comparisons of enzyme presence and to observe trends in enzyme activities. Enzymatic trends were seen in the unionid mussel species, but not in zebra mussels sampled 32 days apart from the same location. Enzymatic classes, based on substrate, showed different trends, with proteolytic and phospholytic enzymes having the most change in relative enzyme activity.

Journal of Shellfish Research